[Samba] 'samba-tool dbcheck' reports only a "Bus error"

[Andrew Bartlett]

On Sun, 2015-10-25 at 16:14 +0100, Ole Traupe wrote:
> For a few days now my primary DC has some issues. I can create users 
> without a problem. But when I try to alter the group membership of 
> users, one of my samba processes crashes (the one listening to the
> LDAP 
> related ports: 389, 636, 3268, 3269).
> 
> Also, when I start my backup DC, a few seconds later another process 
> crashes on the primary DC (the RPC related listening to 135 and
> 1024).
> 
> I haven't made any updates to OS or Samba (still 4.2.2), but I have 
> adjusted some UIDs and GIDs recently.
> 
> Despite "log level = 3", the "log.samba" gives only this,
> 
> [2015/10/22 19:05:46.500567,  0] ../lib/util/fault.c:78(fault_report)
>    ===============================================================
> [2015/10/22 19:05:46.515490,  0] ../lib/util/fault.c:79(fault_report)
>    INTERNAL ERROR: Signal 7 in pid 3794 (4.2.2)
>    Please read the Trouble-Shooting section of the Samba HOWTO
> [2015/10/22 19:05:46.515633,  0] ../lib/util/fault.c:81(fault_report)
>    ===============================================================
> [2015/10/22 19:05:46.515732,  0]
> ../lib/util/fault.c:151(smb_panic_default)
>    PANIC: internal error
> 
> while the trouble shooting page directs me to the log files. ;)
> 
> When I try a 'samba-tool dbcheck' on the PDC, I get the message "Bus 
> error". Nothing more. When I do it on the BDC, the check runs through
> without errors. The sam.ldb on the BDC is in an earlier state because
> replication isn't working any more.
> 
> What does "Bus error" mean? Have I messed up my data base? Or is it 
> something else?

What I suggest is running samba-tool under gdb --args, and then getting
a backtrace.  That will give a clue to where in the C code we are
faulting (if that is the case), and so what the likely issue is.  We
can then proceed to fixing both.

gdb --args python /usr/local/bin/samba-tool

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba